Phosphoric acid generally is produced commercially by one of two methods. One method generally is called the "furnace" method, and the other generally is referred to as the "wet process" method. In the wet process method of producing phosphoric acid, phosphate rock is contacted with a mineral acid such as sulfuric acid. Most phosphate rock contains metal compounds in varying amounts. In many cases, these metal compounds are dissolved from the phosphate rock and appear in the wet process acid as contaminants. Vanadium and uranium compounds are among those dissolved from the phosphate rock, particularly when the rock is from the so-called western deposits of Idaho, Wyoming, Utah and Montana.
Vanadium, however, is an undesirable component of wet process phosphoric acid in that it prevents the use of the phosphoric acid in making animal feed supplements, as the amount of vanadium must be kept at a low level in such animal feed supplements. Similarly, uranium is undesirable in such feed supplements.
On the other hand, vanadium and uranium are valuable materials and wet process phosphoric acid can be an important source of these materials. Therefore, a process for the simultaneous recovery of vanadium and uranium from wet process phosphoric acid provides an important benefit, in that the vanadium and uranium are converted from undesirable contaminants to valuable by-products.